Five teenage boys, none older than 16, have been arrested in the slaying of an off-duty paramedic who was shot April 2 while driving in the Oakland hills, police said Tuesday.

Oakland police officials provided little in the way of motive in the shooting of Quinn Boyer, a Santa Clara County paramedic, other than to say the youths were booked on suspicion of murder, robbery and carjacking.

It remains to be seen what charges the Alameda County District Attorney's Office may bring, as well as whether the teens will be charged as adults.

Their names were not released because of their age, but police said two of the youths are 14 years old, two are 15 and one is 16. All are from Oakland. They were taken into custody in a series of arrests starting Monday night, police said. The youths are not suspected gang members, police said.

"We don't believe there was any external influence," police Lt. LeRonne Armstrong said. "We believe this was a group of young juveniles that were hanging together and got engaged in some real bad behavior."

Boyer, 34, was off duty and stopped at an intersection on the 5200 block of Keller Avenue about noon on April 2 when someone in another car got out and opened fire. Boyer tried to flee in his Honda Civic, but jumped the median and plunged into a ravine. He died April 4 from his injury. His funeral was Tuesday.

Police believe only one of the youths actually fired the shots, but Armstrong said there was more than one related criminal incident involved. He declined to give details, saying the investigation was still active.

The age of the suspects is part of a disturbing trend in Oakland where youths as young as 13 are suspects in violent crimes, Police Chief Howard Jordan said.

He called on parents, school officials and others "to help change the cycle, the vicious cycle, that is taking place in the city where young men and women are finding it very easy and comfortable to point a gun at someone and pull the trigger."

"That is just intolerable," Jordan said.

Police are asking anyone with information about the case to contact the Oakland Police Department at (510) 238-3821 or the toll-free tip hotline at (855) 847-7247.